Online in the import Sounding Grid into the active online Sounding Grid there should be an option to update it on Time. In other words only update the grid cells if the data in the active grid cell is older.
This option is particularly useful when working with dredging equipment (Backhoe Dredgers, CSD, TSHD, ect)
The use case can be that on online grid on a dredger needs to be updated with a survey that is older then some of the dredging updates. The dredging updates should not be overwritten by the older survey data.